Hydraulic tube press



Dec. 27, 1927., 1,654,134

L. LDWY HYDRAULIC TUBE PRESS Filed March 25, 1925 Patented Dec. 27,. 192 7.

UNITED STATES 1,654,134 PATENT orr cs.

LUDWIG Lt D WY, F DUSSELDORF, GERMANY, ASSIGNOR TO SCHLOEMANN AKTIEN- GESELLSCHAFT, 0F DUSSELDORF, GERMANY, A CORPORATION OF GERMANY.

HYDRAULIC TUBE PRESS.

Application filed March 25, 1926, Serial No. 97,251, and in Germany September 2, 1925.

My invention has reference to hydraulic presses for the manufacture of seamless tubes. In presses of this type, the metal from which the tubes are formed, is pressed or extruded while hot through a narrow annular space produced between a matrix and a piercing mandrel, which latter, while the hot metal is being extruded by a large pressplunger, is likewise moved in the direction IQ of the extrusion. The large press-plunger is usually made hollow, and within this hollow press-plunger is concentrically arranged the piercing mandrel, which projects backwardly from the large press-plunger and is guided in a cylinder also provided back of the large press-plunger, where it is rigidly mounted. A drawback of this arrangement is the length of the piston carrying the piercing mandrel which greatly in creases the cost of such presses because of the considerable difliculty experienced in the manufacture and the machining of the long piston, which must be very exactly made and must also be very strong so as to withstand the considerable bending strains to which it is subjected.

The object of the present invention is to eliminate these difficulties which I accom-' plish by providing both the member carrying the piercing mandrel and the guiding member in the large hollow press-plunger, whereby the length of the member carrying the piercing mandrel is considerably shortened, so that special provisions to prevent,

35 bending can be dispensed with. Moreover,

the guiding faces are lengthened, the member carrying thelpiercing mandrel is moved' F or a. more detailed description of my invention, I refer to the appended drawing, in which Fig. 1 is a central sectional view showing an hydraulic press constructed in accordance with my invention; Fig. 2 is a like view showing a modification.

in all the figures, 1 designates the bloclr.

of hot received in the container 2. J

the hydraulic cylinder 5.

while 3 designates the forward end of the large hollow press-plunger l, which is guided in the cylindrical casing 5. 6 is the piercing mandrel, which in passing through a hole in the forward end 3 of press-plunger 4 pierces the hot mass of metal 1 and together with the matrix 7 forms a narrow annular space, through which the hot metal is extruded to form a seamless tube indicated in all the figures at 8.

According to Fig. 1 illustrating one embodiment of my improved hydraulic press, the piercing mandrel 6 is provided at the forward end of a hollow'plunger which is guided within the large press-plunger 4: as well as by a stationary piston 16, extending into the hollow plunger 15 within the large press-plunger 4. The other end of the stationary piston 16 is secured in the cross-head 17 of a standard 18, mounted on Compared withthe well-known press, the presses according to my invention as shown in Fig. 2 is considerably shorter and the relatively movable parts, that is to say, the member (hollow cylinder 15) carrying the picrcingmandrel 6 and the guiding member (piston 16) can be made considerably lighter.

In the modification shown in Fig. 2, the construction is still shorter and more compact than that shown in Fig. 1. According to Fig. 2, the piercing mandrel 6 is provided at the forward end of a movable piston 19 provided within the large pressplunger 4 and guidedwithin a sleeve 20 secured in the bottom of the hydraulic cylinder 5 and extending into the press-plunger 4. The end of piston 19 is provided with a head 21, whereby the piston is guided within said sleeve 20.

The operation of the press either as shown in Fig. 1 or in Fig. 2. is obvious. After the block 1 of hot metal has been placed in the container 2, the forward end 3 of the pressplunger 4 is moved toward the left in Figs. 1 and 2 so as tolightly bear against block 1. Thereupon, the member carrying the piercing mandrel 6 (i. e. cylinder 15 in Fig. 1 or piston 19 in Fig. 2) is moved so that the piercing mandrel will pass through the block 1 of hot metal determining the inner diameter of the tube 8 and forming with the matrix 7 a narrow annular space through which the hot metal is extruded by the grad ual further advance of the forward end 3 llll llll

of press plunger 4, while at the same time, the piercing mandrel 6 is also moved in the direction of extrusion. After all the metal has been extruded, firstly the piercing mandrel is withdrawn and when the residue of the metal has been expelled, the pressplunger is moved back to its original position.

While I have thus described my inven- 1. In a hydraulic press for making seamless tubes, a plunger, a piercing device having a mandrel, and means for operating said piercing device independently of the plunger comprising a relatively movable piston and cylinder, said cylinder slidably engaging the plunger.

2. In a hydraulic press for making seamless tubes, a plunger, a piercing device having a mandrel, and means for operating said piercing'device independently of the plunger comprising a cylinder slidably engaging the plunger, and a piston within the cylinder operatively connected to the piercing device.

In testimony whereof I ailix my signature.

LUDWIG LOW Y. 

